From 36aa7545b0764b6304af7d8dee1b5536eda33f77 Mon Sep 17 00:00:00 2001
From: Alessandro Gatti <a.gatti@frob.it>
Date: Fri, 6 Sep 2024 12:43:54 +0200
Subject: [PATCH] qemu/main: Make GC heap size configurable on a per-arch
 basis.

In certain circumstances depending on the code size, the
`deflate_decompress` test fails on both ARM and RV32 with a memory
allocation failure error.  The issue is mitigated by having a larger GC
heap, in this case around 20 KBytes more than the original 100 KBytes
default.

This commit makes the GC heap size configurable on a per-arch basis, with
both ARM and RV32 using the enlarged 120 KBytes heap.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>
---
 ports/qemu/Makefile  | 4 ++++
 ports/qemu/README.md | 2 ++
 ports/qemu/main.c    | 8 +++++---
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/ports/qemu/Makefile b/ports/qemu/Makefile
index ea0bef814..c8c07965f 100644
--- a/ports/qemu/Makefile
+++ b/ports/qemu/Makefile
@@ -19,9 +19,11 @@ QSTR_DEFS = qstrdefsport.h
 MICROPY_ROM_TEXT_COMPRESSION ?= 1
 
 ifeq ($(QEMU_ARCH),arm)
+MICROPY_HEAP_SIZE ?= 122880
 FROZEN_MANIFEST ?= "require('unittest'); freeze('test-frzmpy', ('frozen_asm_thumb.py', 'frozen_const.py', 'frozen_viper.py', 'native_frozen_align.py'))"
 endif
 ifeq ($(QEMU_ARCH),riscv32)
+MICROPY_HEAP_SIZE ?= 122880
 FROZEN_MANIFEST ?= "require('unittest'); freeze('test-frzmpy', ('frozen_asm_rv32.py', 'frozen_const.py', 'frozen_viper.py', 'native_frozen_align.py'))"
 endif
 
@@ -29,6 +31,8 @@ endif
 include $(TOP)/py/py.mk
 include $(TOP)/extmod/extmod.mk
 
+CFLAGS += -DMICROPY_HEAP_SIZE=$(MICROPY_HEAP_SIZE)
+
 ################################################################################
 # ARM specific settings
 
diff --git a/ports/qemu/README.md b/ports/qemu/README.md
index 9274bcc4e..70edf97f5 100644
--- a/ports/qemu/README.md
+++ b/ports/qemu/README.md
@@ -122,3 +122,5 @@ The following options can be specified on the `make` command line:
 - `QEMU_DEBUG_ARGS`: defaults to `-s` (gdb on TCP port 1234), but can be overridden
   with different qemu gdb arguments.
 - `QEMU_DEBUG_EXTRA`: extra options to pass to qemu when `QEMU_DEBUG=1` is used.
+- `MICROPY_HEAP_SIZE`: pass in an optional value (in bytes) for overriding the GC
+  heap size used by the port.
diff --git a/ports/qemu/main.c b/ports/qemu/main.c
index dff55058e..75c6fe4cd 100644
--- a/ports/qemu/main.c
+++ b/ports/qemu/main.c
@@ -34,14 +34,16 @@
 #include "shared/runtime/gchelper.h"
 #include "shared/runtime/pyexec.h"
 
-#define HEAP_SIZE (100 * 1024)
+#if MICROPY_HEAP_SIZE <= 0
+#error MICROPY_HEAP_SIZE must be a positive integer.
+#endif
 
-static uint32_t gc_heap[HEAP_SIZE / sizeof(uint32_t)];
+static uint32_t gc_heap[MICROPY_HEAP_SIZE / sizeof(uint32_t)];
 
 int main(int argc, char **argv) {
     mp_stack_ctrl_init();
     mp_stack_set_limit(10240);
-    gc_init(gc_heap, (char *)gc_heap + HEAP_SIZE);
+    gc_init(gc_heap, (char *)gc_heap + MICROPY_HEAP_SIZE);
 
     for (;;) {
         mp_init();